JP2003095649A - Method for manufacturing yttria-alumina complex oxide film, yttria-alumina complex oxide film, flame sprayed film, corrosion resistant member and low particle member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an yttria-alumina complex oxide film having a high peel strength to the substrate of the film. SOLUTION: A flame sprayed film consisting of the yttria-alumina complex oxide is manufactured by flame spraying the mixture of an yttria powder and an alumina powder onto the substrate. Preferably 50% of the yttria powder has an average particle diameter of not less than 0.1 μm and not more than 100 μm, and 50% of the alumina powder has an average particle diameter of not less than 0.1 μm and not more than 100 μm. The yttrium-alumina complex oxide preferably contains at least a garnet phase and further a perovskite phase.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a yttria-alumina composite oxide film, a yttria-alumina composite oxide film, a sprayed film, a corrosion resistant member and a low particle member.

[0002]

2. Description of the Related Art Semiconductors requiring a super clean state
In body manufacturing equipment, deposition gas and etching gas
Chlorine gas as a cleaning gas and
Halogen-based corrosive gas such as fluorine-based gas is used
There is. For example, semiconductor manufacturing equipment such as thermal CVD equipment
However, after deposition, ClF_Three, NF _Three, CF_Four,
Consists of halogen-based corrosive gases such as HF and HCl
Semiconductor cleaning gas is used. Also, the deposit
WF at the stage₆, SiH_TwoCl_Two  Such as halo
Gen-based corrosive gas is used as a film forming gas.

Further, in the CVD and PVD film forming processes and etching processes, byproducts are generated due to the chemical reaction, and the byproducts are deposited on the susceptor, electrodes and chamber constituent parts. In the case of an apparatus called a cold wall type, since the temperature of the chamber wall surface is low, particles are easily deposited on the chamber wall surface. These deposits are dry- or wet-cleaned at an appropriate timing, but when the deposits increase, they fall and cause process fluctuations and yield reduction.

As a method of preventing such particles from falling, there is known a method of increasing the holding power by subjecting a metal plate to shot peening or blasting with glass beads or the like to roughen the surface.

[0005]

Therefore, a member for a semiconductor manufacturing apparatus, for example, a member to be housed in the apparatus or an inner wall surface of a chamber, has a high corrosion resistance against halogen gas and its plasma and is stable over a long period of time. Is desired to be formed. Further, when a by-product is deposited on the member housed in the apparatus or the inner wall surface of the chamber, the ability to retain the deposited by-product for a long period of time is desired.

The present applicant has filed Japanese Patent Application No. 2001-110136.
In the specification, it is disclosed that by forming a yttria-alumina garnet film on the surface of the substrate by a thermal spraying method, high corrosion resistance to plasma of halogen gas is imparted and generation of particles can be suppressed. However, this film also had the following problems. That is, cracks may occur in the sprayed film depending on the conditions during spraying. Also, if the thermal spray coating is heat treated at high temperature,
Cracks may occur after the heat treatment. If cracks occur in the film in this way, the film is likely to peel off from the substrate and generate particles, and the corrosion resistance to corrosive substances decreases, so it is not desirable as a product, so the yield It causes a decrease.

An object of the present invention is to provide an yttria-alumina composite oxide film having a high peel strength of the film from a substrate.

Another object of the present invention is to provide a low particle member which has the ability to retain deposits and can be used stably for a long period of time.

Further, an object of the present invention is to provide a low particle member which can firmly hold a deposit on the surface thereof, which makes it difficult for particles to be generated due to the deposit, and can reduce downtime associated with equipment maintenance. It is to be.

[0010]

The invention according to the first aspect is to form a sprayed film of yttria-alumina composite oxide by spraying a mixed powder of yttria powder and alumina powder onto a substrate. The present invention relates to a method characterized by

The present invention also relates to a yttria-alumina composite oxide film obtained by the above method.

The present invention contains a yttria-alumina composite oxide having a garnet phase and a yttria-alumina composite oxide having a perovskite phase, and the peak of the (420) plane of the perovskite phase obtained by X-ray diffraction measurement. Strength YAL (420) and garnet phase (420)
Ratio of peak intensity of surface to YAG (420) YAL (42
0) / YAG (420) is 0.05 or more and 1.5 or less, and is related to the yttria-alumina composite oxide film.

Further, according to the present invention, the length is 3 μm or more and the width is 0.
The present invention relates to a sprayed film made of a yttria-alumina composite oxide, which is characterized by having no cracks of 1 μm or more.

The present invention also provides a corrosion resistant member comprising a substrate and a yttria-alumina composite oxide film,
The yttria-alumina composite oxide film contains a garnet-phase yttria-alumina composite oxide and a perovskite-phase yttria-alumina composite oxide, and has a perovskite phase (42) obtained by X-ray diffraction measurement.
Ratio Y of the peak intensity YAL (420) of the 0) plane and the peak intensity YAG (420) of the (420) plane of the garnet phase
AL (420) / YAG (420) is 0.05 or more,
It is characterized by being 1.5 or less.

Further, the present invention is a corrosion-resistant member comprising a substrate and a sprayed film, wherein the sprayed film is yttria.
It is made of alumina composite oxide and has a length of 3 μm or more and a width of 0.
The present invention relates to a corrosion-resistant member, which is characterized by having no cracks of 1 μm or more.

The invention according to the second aspect is a low particle member comprising a substrate and a surface layer on the substrate, wherein the specific surface area α per unit area calculated by the following formula is 50 or more. , 700 or less. α = (specific surface area by the krypton adsorption method (cm ² /
g)) × (thickness of surface layer (cm)) × (bulk density of surface layer (g / cm ³ ))

The present inventor has conceived that a mixed powder of yttria powder and alumina powder is sprayed on a substrate to form a sprayed film made of yttria-alumina composite oxide.
Carried out. As a result, they have found that a film having a high peel strength with respect to a substrate can be stably formed.

The yttria-alumina composite oxide film thus obtained has no remarkable cracks, has a high peel strength with respect to the substrate, and is unlikely to cause peeling or generation of particles even when it comes into contact with a corrosive substance. Met. Furthermore, when this film was heat-treated, the peel strength of the film to the substrate was further improved, and no crack was observed in the film even after the heat treatment. Not only that, the microstructure can be controlled by further studying the thermal spraying conditions and the heat treatment conditions after thermal spraying, and the porous layer has only open pores or the porous layer has a high open porosity / closed porosity ratio. Succeeded in forming a layer. This not only increased the specific surface area of the component, but also made it possible to hold the deposit firmly by the anchor effect and reduce the thickness of the deposit. by this,
As described in the “invention of the second aspect” described later, a specific α
It became possible to produce films with values.

In a preferred embodiment, the yttria powder has a 50% average particle diameter of 0.1 μm or more and 100 μm or less, whereby cracks can be further suppressed and a corrosive substance, for example, a halogen-based gas plasma. Corrosion resistance is further improved.

Further, from the viewpoint of further improving the adhesion of the film to the substrate, the 50% average particle diameter of the yttria powder is more preferably 0.5 μm or more, further preferably 3 μm or more. Further, from the viewpoint of further improving the adhesive strength of the film to the substrate, the 50% average particle diameter of the yttria powder is more preferably 80 μm or less, further preferably 50 μm or less, and 10 μm.
It is particularly preferable that the thickness is m or less.

In a preferred embodiment, the 50% average particle diameter of the alumina powder is 0.1 μm or more and 100 μm or less. As a result, cracks can be further suppressed and the corrosion resistance of corrosive substances such as halogen gas to plasma is further improved.

Further, from the viewpoint of further improving the adhesive strength of the film to the substrate, the 50% average particle diameter of the alumina powder is more preferably 0.3 μm or more, and further preferably 3 μm or more. Further, from the viewpoint of further improving the adhesive strength of the film to the substrate, the alumina powder 5
The 0% average particle size is more preferably 80 μm or less, further preferably 50 μm or less, and 10 μm.
The following is particularly preferable.

Both yttria powder and alumina powder are 5
The 0% average particle diameter (D50) is the particle diameter of the primary particles when the secondary particles do not exist, and the particle diameter of the secondary particles when the secondary particles exist.

The ratio of yttria particles to alumina particles is not particularly limited. However, when converted to the mol ratio of yttria and alumina (yttria / alumina),
It is preferably 2-1 and more preferably 0.5-0.7.

The mixed powder is yttria powder and
The powder of the third component other than the lumina powder may be included.
However, such a third component is
Garnet phase, perovskite phase of Lumina complex oxide film
It is preferable that it does not adversely affect the crystal phase of
Garnet of yttria-alumina composite oxide
Phase or perovskite phase, yttria or al
It is preferably a component that replaces the mina. like this
The following can be illustrated as the component. La_TwoO_Three, Pr_TwoO_Three, Nd_TwoO_Three, Sm_TwoO_Three, E
u_TwoO_Three, Gd_TwoO_Three, Tb_TwoO_Three, Dy_TwoO_Three, Ho
_TwoO_Three, Er_TwoO_Three, Tm_TwoO_Three, Yb_TwoO_Three, La_Two
O_Three, MgO, CaO, SrO, ZrO_Two, CeO_Two,
SiO_Two, Fe _TwoO_Three, B_TwoO_Three

When spraying the mixed powder, the mixed powder may be sprayed as it is. Alternatively, a binder and a solvent may be added to the mixed powder and granulated by a spray drying method, and the granulated powder may be sprayed.

When spraying the mixed powder, it is preferable to spray the powder under a low pressure, and the pressure is preferably 100 Torr or less. Thereby, the pores of the sprayed film can be further reduced, and the corrosion resistance of the final film can be further improved.

In a preferred embodiment, the sprayed coating can be heat treated to further improve the peel strength of the coating to the substrate.

The heat treatment temperature is preferably 1300 ° C. or higher, more preferably 1400 ° C. or higher. Heat treatment temperature is 13
When the temperature reaches 00 ° C., a reaction layer is likely to be formed between the material of the main body and the material of the corrosion resistant film, and as a result, the peel strength of the film is considered to be improved.

There is no particular upper limit to the heat treatment temperature, as long as it is a temperature at which the body of the member does not deteriorate. From this viewpoint, 2000
It is preferably at most ° C. When the heat treatment temperature of the sprayed film became high and approached 1800 ° C., aluminum element moved and diffused in the vicinity of the reaction layer once formed, and the peel strength of the corrosion resistant film sometimes decreased. From this viewpoint, the heat treatment temperature is preferably 1800 ° C. or lower. Furthermore, from the viewpoint of suppressing the occurrence of cracks in the film, 1700 ° C. or lower is preferable.

The film of the present invention may be continuously present on the surface of the substrate. However, it is not essential that the entire surface of the base body is continuously formed. For example,
Including the case where a plurality of island-shaped layered materials are formed, which are formed discontinuously on the surface of the substrate. It also includes the case where the film is scattered or scattered on a predetermined surface of the substrate.

In a preferred embodiment, the membrane of the present invention is substantially crack-free, in particular of length 3
It is a film having a crack of not less than μm and a width of not less than 0.1 μm. The presence or absence of such microcracks can be confirmed by observing the film with a scanning electron microscope at a magnification of 1000 times or more.

The material of the substrate is not particularly limited. But,
It is preferable to contain no element that may adversely affect the process in the plasma container. From this viewpoint, aluminum, aluminum nitride, aluminum oxide, a compound or solid solution of aluminum oxide and yttrium oxide, zirconium oxide, or a compound or solid solution of zirconium oxide and yttrium oxide is preferable.

The peel strength of the film from the substrate is measured according to the Sebastian test with the diameter of the adhesive surface being φ5.2 mm.

The substrate may be porous. Further, the center line average surface roughness Ra of the surface of the substrate may be 1 μm or more, and further 1.2 μm or more. As a result, the adhesion of the film to the base can be improved, and the generation of particles due to peeling of the film can be suppressed.

The type of yttria-alumina composite oxide is not limited, but is selected from the following, for example. (1) Y ₃ Al ₅ O ₁₂ (YAG: 3Y ₂ O ₃ .5Al
₂ O ₃ ) It contains yttria and alumina in a ratio of 3: 5 and has a garnet crystal structure. _{(2) YAlO 3 (YAL:} Y 2 O 3 · Al 2 O 3).
Perovskite crystal structure. (3) Y ₄ Al ₂ O ₉ (YAM: 2Y ₂ O ₃ .Al ₂ O
₃ ). Monoclinic system.

In a preferred embodiment, yttria
The alumina composite oxide contains at least a garnet phase.
In a preferred embodiment, the yttria-alumina composite oxide contains a garnet phase and a perovskite phase. In such a case, the peel strength of the film from the substrate is further improved, and cracks are less likely to occur.

Particularly preferably, the yttria-alumina composite oxide contains a garnet phase and a perovskite phase, and the peak intensity YAL (420) of the (420) plane of the perovskite phase obtained by X-ray diffraction and the garnet phase. The ratio of the peak intensity of the (420) plane to YAG (420) (YAL (420) / YAG (420)) is 0.
It is not less than 05 and not more than 1.5.

(YAL (420) / YAG (420))
Is particularly preferably 0.05 or more, or particularly preferably 0.5 or less.

The film of the present invention and the laminate of the film and the substrate have excellent corrosion resistance, and particularly have high corrosion resistance against halogen-based gas and plasma of halogen-based gas.

A target for which the corrosion-resistant member of the present invention exhibits corrosion resistance is a semiconductor manufacturing apparatus such as a thermal CVD apparatus. In such a semiconductor manufacturing apparatus, a semiconductor clean gas composed of a halogen-based corrosive gas is used. The corrosion-resistant member of the present invention has corrosion resistance not only in a halogen gas plasma but also in a plasma atmosphere of a gas in which a halogen gas and an oxygen gas are mixed.

As the halogen gas, ClF_Three, N
F_Three, CF_Four, WF₆, Cl _Two, BCl_ThreeEtc.
It

In the invention according to the second aspect, a low particle member comprising a substrate and a surface layer on the substrate, the specific surface area α per unit area is 50 or more, 700
The following low particle member is provided.

According to such a low particle member,
When the generated by-products and particles are deposited on the surface of the low-particle member, the by-products and particles are held in the pores of the surface layer and are unlikely to drop or diffuse from the surface layer. As a result, it is possible to suppress defects caused by dropping and scattering of particles, and it is possible to reduce downtime associated with cleaning deposits.

The specific surface area α per unit surface area is defined by the following formula. α = (specific surface area by the krypton adsorption method (cm ² /
g)) × (thickness of surface layer (cm)) × (bulk density of surface layer (g / cm ³ ))

As can be seen from this formula, α is a kind of index indicating the specific surface area per unit surface area of the surface layer. This surface area value can be calculated from, for example, a design drawing. More specifically, it means the surface area of the surface layer under the assumption that the surface state of the surface layer is smooth without considering the surface irregularities of the surface layer.

Specific surface area by the krypton adsorption method (cm ²
/ G) means (specific surface area per unit weight (g)). That is, it shows how much the surface layer has an adsorption amount per unit weight, that is, how many fine pores are provided.

On the other hand, the thickness of the surface layer (cm) depends on the bulk of the surface layer.
Density (g / cm^Three) Multiplied by the unit surface area of the surface layer
Weight per unit (g / cm^Two) Is obtained. And (single
Specific surface area per unit weight (cm^Two/ G)) for (table
Weight per unit area of surface layer (g / cm^Two) Is multiplied
And (specific surface area per unit surface area (cm ^Two/ Cm^Two)
Is calculated. This is α. Therefore, α is the surface area
1 cm^TwoHow much gas adsorption power there is
Or how many small open pores are present
It will be an index. The bulk density includes open pores and closed pores.
The density is the volume divided by the volume.

In the present invention, α needs to be 50 or more. By providing the surface layer having a large specific surface area α per unit area on the surface of the substrate in this way, by-products and particles can be absorbed, adhered and retained in the open pores of the surface layer, and the particles can be dropped or dispersed. It became possible to suppress. From this viewpoint, α is more preferably 100 or more.

When α is small, the surface area on which the by-product should adhere is small, so even if the amount of the by-product generated is the same, the by-product is deposited thickly on the surface, and as a result, the by-product is deposited. Will fall easily. In addition, since the anchor effect of the surface layer is small, the retention of by-products in the surface layer is also small. The value of α50 or more is obviously large as compared with a general blast finish (refer to Comparative Examples C1 and C2 described later: Tables 3 and 4) of a deposition preventive plate of a sputtering apparatus.

Here, even if the specific surface area α per unit area of the surface layer becomes large, the surface area for adsorbing the particles and by-products increases, so that the particles are prevented from falling or scattering. Thought to be advantageous. However, in practice, it has been found that when the specific surface area α per unit area exceeds 700, the amount of particles falling and the amount of emission increase. This is because when α exceeds 700, when a thermal cycle is applied to the surface layer, the ceramic skeleton forming the surface layer is microscopically damaged and rather becomes a particle source. From this viewpoint, α is more preferably 500 or less, and further preferably 300 or less.

The open porosity of the surface layer is preferably 10% by volume or more, and more preferably 15% by volume or more. This can promote retention of by-products and particles in the surface layer. The open porosity of the surface layer is preferably 30% by volume or less. If this content exceeds 30% by volume, the corrosion resistance of the surface layer and the mechanical strength decrease, so that the surface layer itself becomes a dust source or causes cracks, and on the contrary, the amount of particles tends to increase. There is.

The ratio of the open porosity to the closed porosity of the surface layer (open porosity / closed porosity) is preferably 10 or more. The closed porosity does not contribute to the retention and adsorption of by-products and particles, but rather promotes the corrosion due to the corrosive substance. Therefore, it is desirable that the ratio of the open porosity is high.

In a preferred embodiment, the main open pores of the surface layer have a diameter of 0.05 to 50 μm. By adopting such a pore diameter, the retention and adsorption of by-products and particles in the open porosity can be further promoted.

From another point of view, the pore size should be at the same level as or larger than the design rule of the device to be manufactured. If the device design rule is 0.05 μm, the pore size is 0.05 μm.
The above is preferable.

Because the wafer on which the fine groove is formed is
Once stored and transported under atmospheric pressure in a N2 atmosphere or the like, N2 and moisture are adsorbed also on the fine grooves of the wafer. When this wafer is subjected to the next process such as etching or film formation, it is necessary to degas the components adsorbed in the fine grooves of the wafer in order to secure the stability of the process. The capacity of the exhaust pump of the processing chamber and the exhaust system (thickness of the exhaust pipe and gas flow) are usually designed to allow degassing even from the fine grooves. Therefore, even if pores of the same level as the design rule, which is an index of the fine groove width of the wafer, are vacant on the surface of the film of the present invention, the process is not adversely affected. Further, since the inner area of the container is usually larger than the wafer area, the pore diameter of the membrane of the present invention can be made equal to the design rule from the viewpoint of the total area, but larger pores are more preferable.

From the viewpoint of accelerating the retention and adsorption of by-products and particles, the thickness of the surface layer is 50 μm.
It is preferably not less than 100 μm, more preferably not less than 100 μm.

On the other hand, from the viewpoint of improving the peel strength of the surface layer to the substrate and thereby suppressing the generation of particles, the thickness of the surface layer is preferably 1000 μm or less, more preferably 400 μm or less. preferable.

The material of the surface layer is not particularly limited as long as it has the corrosion resistance required for the intended use. In a preferred embodiment, the material of the surface layer is selected from the group consisting of oxides containing rare earth elements, oxides containing alkaline earth elements, carbides, nitrides, fluorides, chlorides, alloys, solid solutions and mixtures thereof. To be elected. More specifically, the following can be exemplified. Cordierite, diamond, silicon nitride, aluminum nitride, magnesium fluoride, calcium fluoride, aluminum fluoride.

Cordierite is the name of a mineral and has a theoretical composition of 2MgO-2Al ₂ O ₃ -5SiO ₂ composition, but it may also have a solid solution of Fe and alkali. Strictly speaking, it is the name of the low temperature phase of the composition, but usually the high temperature phase is also called cordierite. Here, what mainly consists of cordierite is referred to as cordierite.

Cordierite has excellent corrosion resistance because it contains MgO as a component, and talc (mineral name. 3) as a MgO source.
When MgO-4SiO ₂ -H ₂ O) is used, the talc liquefied during the heat treatment moves into the gaps between the surrounding particles, and the talc remains as pores. The α value can be controlled within an appropriate range by selecting the raw material particle size of talc or the like and the heat treatment conditions.

Diamond can be formed into a film on the surface mainly by the CVD method. Since the diamond itself has a pyramidal shape or a rectangular parallelepiped automorphism, the α value can be selected by controlling the shape and size of the automorphism. In addition, a metal element such as Si is mixed in the film, and then NF
The α value can also be controlled by etching away only the metal element with a fluorine-based plasma such as 3. In the case of diamond, the base material is silicon nitride or silicon carbide,
It is preferable to select aluminum nitride, Si, carbon, or alumina.

It is also possible to use silicon nitride as the surface pore structure. For example, a silicon nitride sintered body using Y ₂ O ₃ and Al ₂ O ₃ as a sintering aid is used in a fluorine-based plasma such as CF ₄ + O ₂ for about 100 to 300
Since heat treatment at ℃ will selectively corrode only silicon nitride, Y ₂
A pore structure composed of an O ₃ —Al ₂ O ₃ —SiO ₂ -based oxide or a Y—Al—Si—NO oxynitride can be obtained. Or KO
Since the grain boundary phase can be selectively dissolved by heat treatment in a molten salt of H: NaOH = 1: 1 (mol ratio) at 300 ° C., a pore structure mainly composed of silicon nitride can be obtained.

As described above, the pore structure of the present invention can be formed not only by the thermal spraying method but also by the sol-gel method, PVD, CVD, precipitation reaction from solution, or paste coating method. . Alternatively, the surface layer may be etched to form a pore structure in the vicinity of the surface layer.

In a particularly preferred embodiment, the surface layer is
It consists of compounds containing yttrium. Such compounds
As a solid solution containing yttria, yttria,
Yttrium trifluoride, a complex oxide containing thoria, is preferred
Good Specifically, yttria, zirconia-yttria
A solid solution, rare earth oxide-yttria solid solution, 3Y_TwoO
_Three． 5 Al_TwoO_Three, YF_Three, Y-Al- (O) -F, Y
_TwoZr_TwoO ₇, Y_TwoO_Three・ Al_TwoO_Three2Y_TwoO_Three・ A
l_TwoO_ThreeCan be illustrated.

More preferably, the surface layer is composed of a yttria-alumina composite oxide produced by spraying a mixed powder of yttria powder and alumina powder onto a substrate. Therefore, as the surface layer material, the yttria-alumina composite oxide film described in the invention according to the first aspect can be diverted as it is.

That is, preferably 50 parts of yttria powder are used.
The% average particle diameter is 0.1 μm or more and 100 μm or less, the 50% average particle diameter of the alumina powder is 0.1 μm or more and 100 μm or less, and the thermal spray coating is heat-treated. Further, preferably, the yttria-alumina composite oxide contains at least a garnet phase. More preferably, the yttria-alumina composite oxide contains a garnet phase and a perovskite phase, and the peak intensity YAL (420) of the (420) plane of the perovskite phase and the (420) of the garnet phase obtained by X-ray diffraction measurement. Ratio of peak intensity of surface to YAG (420) YAL (420)
/ YAG (420) is 0.05 or more and 1.5 or less.

When the low particle member is to be exposed to a corrosive substance, the corrosive substance can be exemplified as follows. Fluorocarbon such as CF ₄ , C ₃ F _6, etc.
Oxygen, chlorine, boron chloride, CHF ₃ , ClF ₃ , SF ₆ , NF ₃ , HB
r, TiCl ₄ , WF ₆ , SiCl ₄ , hydrogen, and mixed gas thereof. It may be mixed with He, N ₂ , or Ar as a carrier gas.

The corrosive substance is particularly preferably the halogen gas or the plasma thereof as described above.

In the present invention, the material of the substrate may have lower corrosion resistance to corrosive substances than the material of the surface layer. This point will be described. As shown in FIG. 1A, the low particle member 1 has a substrate 2 and a surface layer 3 formed on the surface 2 a of the substrate 2. It is assumed that the open pores 4 communicate with each other from the surface 3a of the surface layer 3 to the surface 2a of the substrate 2. 4a is the inner wall surface of the open pore, and 2
Reference numeral b is an exposed surface of the substrate 2 to the open porosity. This open pore 4
Has a small pore diameter as described above, and since the film 3 has a certain thickness, it has an elongated shape (large aspect ratio).

Here, when the low particle member 1 comes into contact with a corrosive substance, the surface layer 3 is corroded as shown in FIG. The dotted line is the contour line before corrosion. Not only the surface 7a of the surface layer 7 is corroded, but also the inner wall surface 6a of the open pores 6 and the exposed surface 2b of the substrate 2 are corroded. Here, when the etching rate of the substrate 2 is higher than the etching rate of the surface layer 7 (is susceptible to corrosion), relatively large holes such as exposed surfaces 2a to 8 of the substrate 2 are generated. However, this hole 8 communicates with the tip of the open porosity 6. On the other hand, the etching rate of the inner wall surface 6a having the open porosity of 6 is relatively small, and therefore the open porosity of 6
The pore size of is not changed so much. As a result, the aspect ratio of open porosity hardly changes after corrosion, but rather increases (becomes elongated). This is an advantageous structure in terms of suppressing dust generation from the base body 2 which is susceptible to corrosion.

The material of the substrate is not particularly limited. But,
It is preferable that no element that may adversely affect the process in the plasma container is contained. From this viewpoint, aluminum, aluminum nitride, aluminum oxide, a compound or solid solution of aluminum oxide and yttrium oxide, zirconium oxide, or a compound or solid solution of zirconium oxide and yttrium oxide is preferable.
In a particularly preferred embodiment, the substrate is made of alumina, spinel, yttria-alumina composite oxide, zirconia, or a composite oxide thereof.

In a preferred embodiment, a compressive stress is applied to the surface layer after forming the surface layer. This method includes heat treatment. This can suppress dust generation from the surface layer.

The method of controlling the specific surface area α of the surface layer per unit area is not particularly limited. Preferably, as described above, a mixed powder of yttria powder and alumina powder is sprayed on the substrate to form a sprayed film, and then the sprayed film is heat-treated. Since the mixed powder reacts at the time of thermal spraying and changes in volume, a large number of pores are generated with this volume change. When the thermal spray coating is heat-treated, the phase transformation of the crystal phase further proceeds,
As a result of further volume contraction, the open porosity increases and α increases. This is a phenomenon discovered by the present inventor.

As another method, etching using an acidic solution or plasma, particularly etching applying selective corrosion can be exemplified. It is possible to control the increase of α also by advanced machining.

[0076]

Example (Experiment A) Each average particle size shown in Table 1 (50%
Each raw material powder having an average particle diameter) was prepared. However,
Of the average particle diameters shown in Table 1, the average particle diameter is 0.1 μm,
0.5 μm, 5 μm yttria particles (Examples A1 to A)
3) are all primary particle diameters, and the average particle diameters of the other yttria particles (Examples A4 to A8) are secondary particle diameters.
Further, the average particle diameters of 0.1 μm, 0.3 μm, 4 μm, 20
Each alumina particle (Example A1-4) of μm has a primary particle diameter, and the average particle diameter of the other alumina particles (A5-8) is a secondary particle diameter.

In Examples A1 to A8 of Table 1, yttria particles and alumina particles were mixed in a weight ratio of 57.1: 42.9. The molar ratio of yttria to alumina is 3: 5. In Examples A1 to A3, yttria powder and alumina powder were wet mixed using a ball mill and granulated with a spray dryer to give an average particle diameter of 40 μm.
Granules of In Examples A4-8, yttria powder and alumina powder were dry mixed.

A base body made of a flat alumina plate having a size of 50 × 50 × a thickness of 2 mm was prepared (alumina purity 9
9.7%). The mixed powder was plasma sprayed on the substrate using a plasma spraying machine manufactured by Sruzer Metco. At the time of thermal spraying, flow argon at a flow rate of 40 liters / minute,
Hydrogen was flown at a flow rate of 12 l / min. Thermal spray output is 4
It was set to 0 kW and the spraying distance was set to 120 mm.

In Example A9, only yttria-alumina garnet powder (average particle size 40 μm) was plasma sprayed onto the substrate under the above conditions. The following measurement was performed about the obtained film of each example.

(Identification of crystal phase) The crystal phase was identified by an X-ray diffractometer. And YAL (420) / YAG (4
20) was calculated. The measurement conditions are as follows. CuKα, 50kV, 300mA, 2 θ = 20-70 ° Device used: Rotating anticathode type X-ray diffractometer "Rigaku Denki" R
INT ””

(Peeling strength) The peel strength was measured as follows. 1. The sample (laminate) after film formation is cut into a size of 10 mm × 10 mm × thickness 2 mm (including film thickness). 2. The cut sample is ultrasonically cleaned with acetone for 5 minutes. 3. An Al stat pin with adhesive (made by Photo Technica Co., Ltd.) is prepared. This bonded area has a diameter of 5.2 m
It has a circular shape of m. 4. The pins are adhered to the film forming surface side. 5. Attach the pin to which the sample is bonded to a jig, pull up the film until it peels off with an autograph, and calculate the bonding strength from the load and the bonding area when the film is peeled off (peeling strength = peeling load / bonding area of pin) . At this time, the value of the sample peeled off at the adhesive portion is not the measured value.

(Presence or absence of crack) Regarding the surface of each film,
It was observed with a scanning electron microscope at a magnification of 5000 times.

(Corrosion resistance test) The samples of the respective examples were set in a corrosion resistance tester, and the test was carried out under the following conditions. Each sample was held for 2 hours in Cl2 gas (heater off). The flow rate of Cl 2 gas was 300 sccm, and the flow rate of carrier gas (argon gas) was 100 sccm. Gas pressure is 0.1 torr, RF800W, bias voltage 31
An output of 0 W was applied. Each sample was weighed before and after the exposure test, and the weight change was calculated.

[0084]

[Table 1]

As can be seen from Table 1, in Example A9, the yttria-alumina garnet powder was sprayed on the substrate, and no perovskite phase was found in the sprayed film. However, the peel strength was relatively low, cracks were observed, and the weight increase after the corrosion resistance test was large. In A1 to A8, the mixed powder was sprayed, but the peel strength was relatively large and no crack was observed. In particular, when the particle size of yttria powder was 0.5 μm to 100 μm and the particle size of alumina powder was 0.3 to 100 μm, the peel strength was 10 MPa or more, no cracks were observed, and the corrosion resistance was particularly high. . In A8, the particle size of the yttria powder and the alumina powder was 120 μm, and the YAM phase was generated. A
In No. 8, the peel strength was relatively high at 13 MPa, but the corrosion resistance was slightly lowered.

(Experiment B) Each of the coating materials of Examples A1 to A9 was heat-treated at 1500 ° C. for 3 hours in the atmosphere. Then, the obtained films of the respective examples were evaluated in the same manner as in Experiment A, and the evaluation results are shown in Table 2.

[0087]

[Table 2]

As can be seen from Table 2, in Example B9, no perovskite phase is found in the sprayed film. However, the peel strength was relatively low, cracks were observed, and the weight increase after the corrosion resistance test was large. In A1 to A8, the mixed powder was sprayed, but the peel strength was relatively large. However, B
In No. 1, a decrease in peel strength and cracks were observed after the heat treatment. Especially, the grain size of yttria powder is 0.5
μm to 100 μm, and the particle size of the alumina powder is 0.3 to
When it was 100 μm, the peeling strength was 40 MPa or more, which was extremely high, and no crack was observed.

In B4 to B8, after the heat treatment, YAL
The peak intensity of the phase was significantly increased. This tendency was particularly remarkable in B6, B7, and B8. In A8, the peak intensity ratio YAL (420) / YAG (420) was 1.
Although it exceeded 5, no crack was observed and the peel strength did not decrease so much. However, the weight increase after corrosion resistance was large. This is considered to be due to the difference in crystal phase of the film. As described above, according to the present invention, it is possible to provide a yttria-alumina composite oxide film having a high peel strength of the film from the substrate.

(Experiment C) Experimental Examples C1 to C1 shown in Tables 3 and 4
16 members were manufactured. However, in C1, the dense alumina sintered body was blasted with # 80 abrasive grains,
Then, it was processed to a thickness of about 400 μm to obtain a free-standing film test piece. C
In 2 and C3, YAG powder having an average particle size of 40 μm was sintered at 1600 ° C. or 1500 ° C. to obtain each sintered body. Then, each sintered body was blast-finished with # 80 abrasive grains and then processed to a thickness of about 400 μm to obtain a free-standing film test piece.

In C4 to C16, the height is 1
In the same manner as in Experiment A, a sprayed film was formed on two substrates having a size of 50 mm, a width of 150 mm and a thickness of 5 mm. And Experiment C
In No. 4 and C8-16, the obtained thermal spray coating was heat-treated. For each test piece, the peak strength ratio, peel strength, presence of cracks, corrosion resistance test results, porosity, specific surface area (cm ² / g) by krypton adsorption method, average film thickness, α, mercury intrusion volume, pore diameter The number of particles was measured.

(Α) For the specific surface area by the Kr method, the Kr gas adsorption multipoint BET method was used. The bulk density of the surface layer was 4 g / cm ³ . (Mercury intrusion volume, pore diameter) A mercury intrusion porosimeter was used to measure the pore size in the range of 1 nm to 200 μm. Since the pore size has a distribution, Table 4 shows the range of sizes in which the main peaks exist. The surface tension value of mercury was 485 erg / cm ² and the contact angle was 130 °. (Porosity) Obtained by the Archimedes method. C7-C16
As for the above, it was confirmed from the ratio of apparent specific gravity and bulk specific gravity obtained by the same method that the pores consist essentially of open pores.

(Number of Particles) 35 g of the alumina powder used in Comparative Example C1 was suspended in 100 to 1000 cc of pure water, each sample of C1 to 16 was dipped therein, and then 120
It was dried at ° C. By repeating this operation until the suspension disappeared, almost the entire amount was deposited on the test piece. With the surface layer coated surface facing downward, a heat cycle from room temperature to 200 ° C. was applied 50 times, and the number of particles on the Si wafer placed below was counted.

[0094]

[Table 3]

[0095]

[Table 4]

In C1 and C2, since they are dense sintered bodies, they have no ability to retain particles, and many particles fell from the sintered body to the wafer. In C3,
Due to insufficient sintering of YAG, α became very large.
This is because there are many fine open pores due to insufficient sintering. In this case, many particles rather fell after the heat cycle. In C4, α of the surface layer was small, and many particles fell.
The large number is approximately 10,000 or more. C5 of the present invention example
In ~ 16, the particles were prevented from falling onto the wafer. Particularly, C8 to C16 were good. It is considered that the porosity is higher than C5 to C7. From the viewpoint of peel strength, C11 to C16 are particularly excellent.

In the examples of the present invention, for both C5 and C16, a mixed powder of yttria powder and alumina powder was sprayed to form a sprayed film. In C5, 6, and 7, the heat treatment of the sprayed film was not performed, so the porosity was less than 10%. In C8 to 16, as a result of the heat treatment, the porosity increased and exceeded 10%.

In Experiments C5 to 16, the peak intensity ratio was in the range of 0.05 to 1.5, the peel strength was high, and no crack was observed.

(Example C17) Talc having a particle size of 10 μm and fused quartz, and an alumina raw material having a particle size of 25 μm were kneaded with methylcellulose and water to form a paste, which had a length of 150 mm and a width of 150 mm similar to C4 to C16. It was applied to an alumina base material having a thickness of 5 mm, and then heat-treated at 1400 ° C. in the atmosphere. This process was repeated several times to form a cordierite layer having an average thickness of 120 μm. Bulk density for calculating α value is 2.0 g / cm
³ was used. The peel strength was 36 MPa, and no crack was found. Corrosion resistance test weight gain was -0.3 mg / hour, porosity was 21%, average film thickness was 120 μm.
And α is 139, and the mercury injection volume is 0.102.
cc / g, the pore size range is 1-40 μm, and the number of particles is 0.

(Example C18) In the case of diamond, the base material was silicon nitride. The manufacturing method is as follows: 5 mol% Y ₂ O ₃ and 2 mol% Al ₂ O ₃ and 5 mol% β-type silicon nitride are added to and mixed with α-type silicon nitride powder having a particle size of about 1 μm, and then mixed at 1850 ° C. in a nitrogen atmosphere. It has been densified with. The shape of the base material
Similar to C17. About 5 by the microwave CVD method on this substrate
A 0 μm thick diamond film was formed. Quartz glass was placed around the substrate, and Si and oxygen were mixed in the diamond film. Next, the substrate structure was exposed to down-flow plasma of NF ₃ + Ar mixed gas for 10 hours while the substrate temperature was in the range of 150 to 300 ° C. to form a pore structure. The bulk density for calculating the α value was 3.2 g / cm ³ . The peel strength was 54 MPa, and no crack was found. The corrosion resistance test weight increase was 0.0 mg / hour, the porosity was 10%, the average film thickness was 50 μm, α was 53, and the number of particles was 0.

As described above, according to the present invention, it is possible to provide a low particle member which can firmly hold the deposit on the surface thereof and in which particles due to the deposit are less likely to be generated.

[Brief description of drawings]

1A is a sectional view schematically showing a low particle member 1 before corrosion, and FIG. 1B is a sectional view schematically showing a low particle member 1 after corrosion.

[Explanation of symbols]

1 Low particle member before corrosion 2 Substrate
2a Surface of substrate 2 2b Surface exposed to open pores 3 Surface layer before corrosion 3a Surface before corrosion 4 Open pores before corrosion 4a Open pore inner wall surface before corrosion 6 Open pores after corrosion
6a Inner wall surface of open pores after corrosion 8 Corroded portion of substrate 2

Continued front page    F-term (reference) 4G076 AA02 AA18 AB02 AB16 BA38                       CA10 CA29 CA31 CA33 DA30                 4K031 AA01 AB02 AB09 CB14 CB16                       CB42 CB43 CB49 DA04 FA01                 5F045 BB15 EB03 EB06

Claims (38)

[Claims] 1. A yttria-alumina composite oxide film, characterized in that a sprayed film of yttria-alumina composite oxide is formed by spraying a mixed powder of yttria powder and alumina powder onto a substrate. Production method. 2. The method according to claim 1, wherein the 50% average particle diameter of the yttria powder is 0.1 μm or more and 100 μm or less. 3. The method according to claim 1, wherein the 50% average particle diameter of the alumina powder is 0.1 μm or more and 100 μm or less. 4. The method according to claim 1, wherein the sprayed film is heat-treated. 5. The method according to claim 1, wherein the yttria-alumina composite oxide contains at least a garnet phase. 6. A yttria-alumina composite oxide film obtained by the method according to any one of claims 1 to 5. 7. The yttria-alumina composite oxide film according to claim 6, which has no cracks having a length of 3 μm or more and a width of 0.1 μm or more. 8. The yttria-alumina composite oxide contains a garnet phase and a perovskite phase, and (42) of the perovskite phase obtained by X-ray diffraction measurement is used.
The ratio YAL (420) / YAG (420) between the peak intensity YAL (420) of the 0) plane and the peak intensity YAG (420) of the (420) plane of the garnet phase is 0.05 or more and 1.5 or less. The yttria-alumina composite oxide film according to claim 6 or 7, characterized in that. 9. A peak intensity YA of a (420) plane of the perovskite phase, which is obtained by X-ray diffraction measurement and contains a garnet phase yttria-alumina composite oxide and a perovskite phase yttria-alumina composite oxide.
Ratio YAL (420) / Y of L (420) and peak intensity YAG (420) of the (420) plane of the garnet phase
An yttria-alumina composite oxide film having an AG (420) of 0.05 or more and 1.5 or less. 10. The yttria-alumina composite oxide film according to claim 9, which is free from cracks having a length of 3 μm or more and a width of 0.1 μm or more. 11. The yttria-alumina composite oxide film according to claim 9, which is formed by a thermal spraying method. 12. A thermal spray coating of yttria-alumina composite oxide, characterized in that it has no cracks having a length of 3 μm or more and a width of 0.1 μm or more. 13. The yttria-alumina composite oxide contains a garnet phase and a perovskite phase, and the (4) of the perovskite phase obtained by X-ray diffraction measurement is used.
The ratio YAL (420) / YAG (420) between the peak intensity YAL (420) of the 20) plane and the peak intensity YAG (420) of the (420) plane of the garnet phase is 0.05 or more and 1.5 or less. 13. The thermal spray coating according to claim 12, wherein 14. A corrosion resistant member comprising a substrate and a yttria-alumina composite oxide film, wherein the yttria-alumina composite oxide film is a garnet phase yttria-alumina composite oxide and a perovskite phase yttria. -Containing an alumina composite oxide,
Peak intensity YAL (420) of the (420) plane of the perovskite phase and peak intensity YAG (420) of the (420) plane of the garnet phase obtained by X-ray diffraction measurement
The ratio YAL (420) / YAG (420) is 0.0
The corrosion-resistant member is characterized by being 5 or more and 1.5 or less. 15. The corrosion-resistant member according to claim 14, wherein there are no cracks having a length of 3 μm or more and a width of 0.1 μm or more. 16. The corrosion resistant member according to claim 14, wherein the yttria-alumina composite oxide film is formed by a thermal spraying method. 17. The corrosion resistant member according to claim 14, wherein the yttria-alumina composite oxide film has a peel strength of 10 MPa or more with respect to the substrate. 18. A corrosion-resistant member comprising a substrate and a sprayed film, wherein the sprayed film is made of yttria-alumina composite oxide and has no cracks having a length of 3 μm or more and a width of 0.1 μm or more. A corrosion resistant member characterized by: 19. The yttria-alumina composite oxide contains a garnet phase and a perovskite phase, and the (4) of the perovskite phase obtained by X-ray diffraction measurement is used.
The ratio YAL (420) / YAG (420) between the peak intensity YAL (420) of the 20) plane and the peak intensity YAG (420) of the (420) plane of the garnet phase is 0.05 or more and 1.5 or less. The corrosion-resistant member according to claim 18, characterized in that: 20. The corrosion resistant member according to claim 18, wherein the yttria-alumina composite oxide film has a peel strength of 10 MPa or more with respect to the substrate. 21. The corrosion resistant member according to any one of claims 14 to 20, which is a corrosion resistant member to be exposed to a halogen gas or a plasma of a halogen gas. 22. A low particle member comprising a substrate and a surface layer on the substrate, wherein α calculated by the following formula is 50 or more and 700 or less. α = (specific surface area by the krypton adsorption method (cm ² /
g)) × (thickness of surface layer (cm)) × (bulk density of surface layer (g / cm ³ )) 23. The open porosity of the surface layer is 10% by volume or more and 30% by volume or less.
The member described in 2. 24. The member according to claim 22, wherein the surface layer has a ratio of open porosity to closed porosity (open porosity / closed porosity) of 10 or more. 25. The diameter of the main open pores of the surface layer is 0.
25 to 50 μm.
25. A member according to any one of claims 24. 26. The member according to claim 22, wherein the thickness of the surface layer is 50 μm or more. 27. The surface layer is selected from the group consisting of oxides containing rare earth elements, oxides containing alkaline earth elements, carbides, nitrides, fluorides, chlorides, alloys, solid solutions and mixtures thereof. The member according to any one of claims 22 to 26, which is made of a material. 28. The member according to claim 22, wherein the surface layer is made of a compound containing yttrium. 29. The member according to claim 28, wherein the surface layer contains a yttria-alumina composite oxide. 30. The low particle member is to be exposed to a corrosive substance, and the base material is
23. The etching rate of the corrosive substance is higher than that of the material of the surface layer.
29. A member according to any one of claims 29. 31. The member according to claim 30, wherein the corrosive substance is halogen gas or plasma of halogen gas. 32. The method according to claim 22, wherein the substrate is made of a material selected from the group consisting of alumina, spinel, yttria, zirconia, and composite oxides thereof. The member described in. 33. The surface layer is a sprayed film made of a yttria-alumina composite oxide produced by spraying a mixed powder of yttria powder and alumina powder onto a substrate. 33. A member according to any one of claims 32 to 32. 34. The member according to claim 33, wherein the 50% average particle diameter of the yttria powder is 0.1 μm or more and 100 μm or less. 35. The member according to claim 33, wherein the 50% average particle diameter of the alumina powder is 0.1 μm or more and 100 μm or less. 36. The member according to claim 33, wherein the thermal spray coating is heat treated. 37. The member according to claim 33, wherein the yttria-alumina composite oxide contains at least a garnet phase. 38. The yttria-alumina composite oxide contains a garnet phase and a perovskite phase, and the (4) of the perovskite phase obtained by X-ray diffraction measurement is used.
The ratio YAL (420) / YAG (420) between the peak intensity YAL (420) of the 20) plane and the peak intensity YAG (420) of the (420) plane of the garnet phase is 0.05 or more and 1.5 or less. 38. A member according to claim 37, characterized in that